Apparatus for reciprocating a traveller

ABSTRACT

APPARATUS FOR RECIPROCATING A TRAVELLER CARRYING A YARN GUIDE FOR DELIVERING YARN TO BE WOUND ON A BOBBIN INCLUDING AN ENDLESS BELT DRIVEN BY A PAIR OF PULLEYS AND CARRYING A SHOE SLIDABLY ENGAGING A GROOVE IN THE TRAVELLER, THE GROOVE HAVING A PAIR OF SYMMERIC CURVED BRANCHES FOR ALTERNATIVELY RECEIVING THE SHOE AS THE SHOE IS MOVED AROUND THE PULLEYS, WHEREBY THE SINUSOIDAL CHANGE IN LINEAR SPEED OF THE TRAVELLER AS THE SHOE MOVES AROUND THE PULLEYS IS COMPENSATED.   D R A W I N G

Feb. 1 3, 1973 w. E. sm'rom APPARATUS FOF RECIPROCATING TRAVELLER Y Filed Oct, 21 1.9m s Shedts-Sheet 1 Q Feb. H3, 1973 R. SARfORi 5 Sheets-Sheet a Filed Oct. 21 i971 mw m 1973 RQ sA -Qm m1 APPARATUS FOR nncxrajocmmo TRAVELLER Filed Oct. 2'1f-1971 v asn-ets-sneei s- United States Patent 3,716,200 APPARATUS FOR RECIPROCATIN G A TRAVELLER Roland Ernest Sartori, Riorges, France, assignor to Ateliers Roannais de Constructions Textiles, Roanne,

France Filed Oct. 21, 1971, Ser. No. 191,227 Int. Cl. B65h 54/30 US. Cl. 242-43 6 Claims ABSTRACT OF THE DISCLOSURE Apparatus for reciprocating a traveller carrying a yarn guide for delivering yarn to be wound on a bobbin including an endless belt driven by a pair of pulleys and carrying a shoe slidably engaging a groove in the traveller, the groove having a pair of symmetric curved branches for alternately receiving the shoe as the shoe is moved around the pulleys, whereby the sinusoidal change in linear speed of the traveller as the shoe moves around the pulleys is compensated.

BACKGROUND OF THE INVENTION Field of the invention The present invention pertains to apparatus for reciprocating a traveller and, more particularly, to such apparatus wherein the traveller is reciprocated with constant linear speed by an endless belt.

Discussion of the prior art In the textile industry, yarns are wound in the form of cross-wound packages by means of yarn guides actuated with a traverse motion which is most often imparted by a revolving cam moving a traveller integral with a bar carrying the yarn guides.

This system is satisfactory at linear winding speeds on the order of 100 meters per minute at the most and at reciprocating frequencies corresponding thereto. At higher linear speeds, the forces of inertia at the extremities of the traversing movement, i.e., at the turning-back points, reach a prohibitive value causing rapid wearing of the cam and traveller. Accordingly, the cam and traveler work loose and skip or slip which further increases the Wear and tear as well as causing winding defects, in particular wadding and dropped coils or whorls. These winding defects will later present difiiculties in unwinding the bobbins, increasing the risk of breakage. Moreover, the wadded portions and dropped coils unravel more easily and, therefore, increase the risk of breakage which causes a loss of efliciency when the bobbins are used during weaving, knitting, and other textile operations.

It has been proposed to impart a continuous movement to a yarn guide by attaching it to a strap or belt passing over two pulleys. This system permits a substantial increase in linear winding speed; however, unless extremely small diameter pulleys are used, which pulleys are not capable of non-slip driving of the belt, the trip or movement around the pulleys is somewhat long relative to the two straight runs between the pulleys where the speed of the yarn guide is constant. In the curved trips around the pulleys, the speed parallel to the axis of the bobbin slows down progressively according to a sinusoidal law, which results in sizable wads or bunches leading to the defects mentioned above.

According to another known system for continuous movement guiding, two adjacent parallel belts or one belt with two parallel loops carrying guides may be used. In the case of two parallel belts, the two belts travel in opposite directions; in the case of a single belt with loops, two sides of the belt travel in opposite directions. In this system, the yarn is guided linearly at a constant speed by a yarn guide on one belt and, at the end of the traverse, is picked up immediately by a guide on the other belt for the opposite traverse. The system operates similarly with the use of the single belt with two loops. The major disadvantage of this system is that it is difficult to avoid missed or defective releases and resulting para sitic or extra windings occur.

Attempts have been made to compensate for the sinusoidal slowing down at the extremities of the traverses by correcting for the movement of the traveller; however, such correction has been only partially and imperfectly performed, and mechanical defects of the proposed systems have not been overcome.

In French Pat. 2,072,424 apparatus is disclosed for compensating for the change of speed of a traveller at the extremities of a traversing path by utilizing a coupling member movable in a first guide groove while traveling around one extremity and movable in a second guide groove while traveling around the opposite extremity. The configuration of the guide grooves is related to the movement of the coupling member in order to maintain the speed of the traveller linear; however, the apparatus of the French patent suffers from the disadvantage that the coupling member may move in the wrong guide groove at the extremity of a travel.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide apparatus for moving an element with traversing or reciprocating action at a constant linear speed, particularly at the ends of the reciprocating movement.

The present invention is generally characterized in an improvement in apparatus for reciprocating a traveller with constant speed including a yarn guide mounted on the traveller, an endless belt passing over a pair of pulleys, and a shoe carried by the belt and engaging the traveller, the traveller having a groove therein with a pair of symmetric curved branches for alternately receiving the shoe when the shoe is moved around the pulleys, the im provement including upper and lower racks carried by the traveller for engaging curved racks extending from the pulleys as the shoe moves around the pulleys to assure the shoe riding in the proper branch of the groove.

Another object of the present invention is to provide rapid traverse motion with constant linear speed either far or close to the extremities of the traverse utilizing an endless belt passing over two pulleys.

A further object of the present invention is to compensate for the loss of speed due to the curved portions of the traverse to maintain a constant linear speed.

The present invention has another object in that a yarn guide is carried by a traveller having two curved symmetrical grooves in which travel a shoe turning on a pivot integrally carried by an endless belt over a pair of pulleys. One of the grooves guides the shoe during the course of the belt around one of the pulleys, and the other groove guides the shoe during the corresponding opposite course of the belt around the other pulley.

An additional object of the present invention is to assure the traveling of a shoe in the correct branch of a grooved traveller by providing racks on the traveller to engage curved racks extending from a pair of pulleys during movement of the shoe around the pulleys.

Between the pulleys the belt travels a straight path and has a uniform linear speed since the pulleys are driven at a constant speed. Designating as (p the angle between the radius of one of the pulleys and the point where the straight run of the belt stops, the linear speed of the shoe in the direction of the straight run is equal to V cos (,0, V being the linear speed of the belt and its tangential speed around the curved portions of the pulleys. In order to maintain the speed of the traveller and yarn guide constant there is added thereto a complement V(lcos (p) corresponding to a half cycle of a sinusoidal curve.

One of the advantages of the present invention is that the shoe, traveller and the yarn guide may be very light, for example having a weight of a few grams, thereby reducing the forces of inertia during the abrupt turning back of the shoe at the end of each traverse.

Other objects and advantages of the present invention will become apparent from the following description of a preferred embodiment taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of apparatus for reciprocating a traveller according to the prior art.

FIG. 2 is a schematic representation of apparatus for reciprocating a traveller with constant linear speed acording to the present invention.

FIG. 3 is a side elevation of the endless belt and pulleys of the apparatus of FIG. 2.

FIG. 3A is a plan view of the arm and shoe supported on the endless belt of FIG. 3.

FIG. 3B is a broken perspective view of the arm and shoe supported on the endless belt of FIG. 3.

FIG. 4 is a side elevation of a traveller and pulley according to the present invention.

FIG. 4A is a side elevation of a support track for the apparatus of the present invention.

FIG. 5 is a broken perspective view of the apparatus of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Apparatus for reciprocating a traveller according to the prior art is illustrated in FIG. 1 and will be described hereinafter in order to appreciate the problems overcome by the present invention. The apparatus of FIG. 1 includes an endless belt passing around a pair of wheels or pulleys 12 and 14 disposed at either extremity of the reciprocating or traversing path for a traveller 16. Traveller 16 carries a yarn guide, not shown, which normally includes a split or bifurcated member through which the yarn to be guided passes prior to winding on a bobbin. Traveller 16 has a groove 18 therein extending transversely to the direction of reciprocating movement of the traveller, and a shoe 20 is slidably received in groove 18 and is mounted in any suitable manner so as to be integrally moved with the belt 10.

In operation, the traveller 16 is reciprocated back and forth between the extremities of traverse indicated at A and B by the belt 10 moving in the direction of the arrow. Thus, the traveller 16 is moved from B to A with the shoe 20 received in a top portion of groove 18 and is moved from A to B with the shoe received in a lower portion of groove 18. The traveller 16 and hence, the yarn guide will experience a constant linear speed between the straight portions of the run of belt 10 due to a constant driving of either of pulleys 12 or 14; that is, between points H and C and points E and F the linear speed of the traveller will be constant. Once the shoe 20 reaches point C, however, the linear speed of the traveller will begin to decrease as a function of V cos go as abovementioned where V is the linear speed of the belt 10 and (p is the angle between a radius of the pulley 12 corresponding to a position of shoe 20 at any moment and the point C where curved movement of the shoe around the pulley begins. Accordingly, the linear speed of traveller 16 is reduced according to a sinusoidal function and gradually decreases to become zero at turning back point D coinciding with the intersection of a line XY through the axes of pulleys 12 and 14 and the extremity of traverse A. From point D to point E, which is the point where the shoe enters the straight run of belt 10 and experiences no further curved movement, the linear speed of the traveller 16 will increase according to the sinusoidal function.

A similar decrease and increase in linear speed is experienced as shoe 20 moves around pulley 14 such that between point F, which corresponds to point C and is the point at which curved movement of the shoe 20 around the pulley 14 begins, and turning back point G, which corresponds to point D and is at the intersection of a line through the axes of pulleys 12 and 14 and traverse extremity B, the linear speed of the shoe decreases sinusoidally; and, from point G to point H, which corresponds to point E and is the point at which the shoe enters the straight run of belt 10 and experiences no further curved movement, the linear speed of the shoe increases sinusoidally.

The apparatus of the present invention is schematically illustrated in FIG. 2 and shown in perspective in FIG. 5, and parts of the apparatus which are identical to parts of the apparatus of FIG. 1 are given identical reference numbers and are not described again. The apparatus includes a traveller 22 riding on a pair of parallel guide rods 23 and having a groove 24 therein extending transversely to the direction of reciprocating movement of the traveller. The groove 24 has an upper portion 26, a lower portion 28 and a pair of symmetric curved branches 30 and 32 communicating therebetween. The curved branches 30 and 32 are each provided with a sinusoidal configuration corresponding to the function lcos (,0 such that, as will be explained in more detail hereinafter, the addition of the linear speed during curved motion of the shoe 34 of V cos (p with the relative speed between shoe 34 and the traveller 22 of V(1cos (p) is equal to V whereby the linear speed of the traveller is maintained substantially constant between extremities of the traverse.

As is best illustrated in FIG. 3, the belt 10 carries inwardly projecting teeth which mesh with outwardly projecting teeth on pulleys 12 and 14 in order to precisely control the speed of the belt by cogged engagement with the pulleys, and belt 10 carries a cylindrical mounting sleeve 36 integrally therewith, such as by vulcanizing the sleeve to the belt, which sleeve 36 houses a rod 38 pivotally carrying shoe 34 as can be seen from FIGS. 3A and 3B. Pulleys 12 and 14 each have an arcuate recess 40 therein having a configuration complementary to that of sleeve 36 in order to accommodate the sleeve 36 as the shoe 34 is moved around the pulleys. Of course, the length of belt 10 will be a precise multiple of the periphery of, the pulleys 12 and 14 in order to assure precise indexing of the sleeve 36 in the recesses 40 during operation.

It is important that the shoe 34 slidably engage the appropriate branch of groove 24 at each extremity of the traverse; and, in order to guarantee such proper sliding engagement, the traveller 22 has upper and lower bifurcated, toothed racks 42 and 44 with the space between the racks accommodating movement of shoe 34 in the upper portion 26 and the lower portion 28 of the groove. The teeth of racks 42 and 44 are disposed in diametric opposition, and pulleys 12 and 14 each carry a toothed segment 46 offset from belt 10 and extending sufiiciently to mesh with the racks 42 and 44. The segment 46 is centered about the recess 40 in the pulley such that as the shoe 34 experiences curved movement around the pulley, the segment 46 will engage rack 42 to assure that the shoe rides in branch 30. Once the shoe has entered the branch 30, the segment 46 and rack 42 will disengage, such as at point J in FIG. 4, and segment 46 will thereafter engage rack 44 at point K in order to facilitate the launching of the traveller 22 in the opposite direction after passing turning back point D. The operation as abovedescribed is identical as the shoe 34 is moved around pulley 14 at the opposite extremity of the traverse.

With the use of the racks 42 and 44 in combination with the toothed segments 46 carried by the pulleys, a control angle on defines the deceleration path between point I and turning back point D and the acceleration path between point D and point K. Tne configuration of branches 3t and 32 of groove 24 at the turning back point must be attenuated or reduced and are therefore, given the configuration or profile of an arc of a circle or a lemniscate or other outlines.

In order to relieve the stress on the traveller 22, the rod 38 and the shoe 34 at the turning back points D and G of the traverse, a guide or support track 48 is disposed in spaced relation from the outer periphery of the pulleys 12 and 14. Support track 48 is preferably disposed, as illustrated in FIG. 4A, in order to engage the sleeve 36 thereby guiding the movement of the sleeve and shoe around the pulleys 12 and 14.

A yarn guide 50 extends from the traveller 22 on the side opposite the pulleys l2 and 14 and is adapted to guide a yarn 52 for winding around a bobbin during reciprocating movement of the traveller. The yarn guide 50 has a slit 54 therein for receiving the yarn, and a feeler may be disposed adjacent the slit in order to detect accidental escape of the yarn therefrom.

In operation, the traveller 22 and the yarn guide 50 are moved with constant linear speed during the straight runs of the belt 10 due to the constant rotational drive of one of the pulleys 12 and 14; and, once the sleeve 36 reaches point C where the shoe 34 begins curved move ment around the pulley 12, the shoe 34 will be received in branch 30 such that the relative speed between the shoe 34 and the traveller 22 is defined by V(l-cos This speed added to the linear speed of shoe 34 defined by V cos 90 provides a substantially constant linear speed between extremities of the traverse. Similarly, when sleeve 36 approaches pulley 14, the shoe 34 will ride in branch 32 of groove 24 to thereby compensate for the sinusoidal increase and decrease in linear speed during curved movement of the shoe in the same manner.

The branches 30 and 32 are symmetric, and each branch curves outwardly from the center of the traveller in order to properly compensate for the sinusoidal variation in linear speed. When the shoe 34 experiences a curved movement in a first direction corresponding to movement around a pulley, the shoe will ride in the curved branch of the groove in the traveller having an opposite curved direction to that of the movement around the pulley, such that the shoe alternately rides in branches 30 and 32.

From the above, it can be seen that the apparatus of the present invention utilizes grooves for receiving a shoe in order to provide a complement of the sinusoidal increase and decrease in linear speed of a traveller as a shoe engaging the traveller rides around a curved pulley and that a method according to the present invention includes the steps of reciprocating a traveller with an endless belt moving around a pair of pulleys and carrying a shoe engaging the traveller wherein the shoe has a linear speed of V cos zp when the shoe is moved around the pulleys, and compensating for the change in linear speed of the shoe moving around the pulleys by moving the traveller relative to the shoe with a linear speed of Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter above-described or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In apparatus for reciprocating a traveller with constant linear speed for use in Winding machines including a guide mounted on said traveller for guiding yarn for winding, first and second pulleys, an endless belt passing over said first and second pulleys, and shoe means carried by said endless belt and slidably engaging said traveller, said traveller having a groove therein extending transverse to the direction of movement of said traveller, said groove having first and second symmetric curved branches for alternately receiving said shoe means when said shoe means is moved around said first and second pulleys such that the linear speed of said traveller is maintained constant at the ends of the reciprocating movement, the improvement comprising upper and lower racks carried by said traveller and curved racks extending from said first and second pulleys to engage said traveller racks as said shoe means moves around said pulleys to assure said shoe means riding in the proper branch of said groove.

2. The apparatus as recited in claim 1 wherein said shoe means rides in said first branch when moving around said first pulley and in said second branch when moving around said second pulleys, said first and second branches each curving outward from the center of said traveller.

'5. The apparatus as recited in claim 2 wherein said first and second pulleys are toothed and said belt has teeth engaging the teeth of said pulleys.

4. The apparatus as recited in claim 1 and further comprising a pair of parallel rods, said traveller riding on said parallel rods.

5. The apparatus as recited in claim 1 and further comprising track means disposed adjacent each of said first and second pulleys and having a curved surface spaced from the outer periphery of said pulleys to guide said shoe means in movement around said pulleys to facilitate the change in direction of movement of said shoe means.

6. The improvement as recited in claim 1 wherein said upper and lower traveller racks are each bifurcated and said groove has an upper portion extending between the halves of said upper traveller rack and a lower portion extending between the halves of said lower traveller rack.

References Cited UNITED STATES PATENTS 3,602,447 8/1971 Fisher 24243 FOREIGN PATENTS 1,205,879 9/1970 Great Britain 242158 B STANLEY N. GILREAT H, Primary Examiner US. Cl. X.R. 242158 B 

